# File lib/fog/aws/requests/storage/put_object.rb, line 32
        def self.conforming_to_us_ascii!(keys, hash)
          return if RUBY_VERSION =~ /^1\.8\./
          keys.each do |k|
            v = hash[k]
            if !v.encode(::Encoding::US_ASCII, :undef => :replace).eql?(v)
              raise Excon::Errors::BadRequest.new("invalid #{k} header: value must be us-ascii")
            end
          end
        end